Best way to widen P90 cover holes

[Zhangliqun]

Trying to make a rod magnet P90 for a customer with rods larger than the holes in a typical P90 cover. The covers are kind of brittle for drilling and tend to crack or shatter.

What's the best way to go about this?

[David Schwab]

A reamer would work.

[mick]

Blunt drill bit , slow speed and make sure the cover is warm not cold..

mick

[Spence]

22 caliber rifle. Works every time!

[Joe Gwinn]

Trying to make a rod magnet P90 for a customer with rods larger than the holes in a typical P90 cover. The covers are kind of brittle for drilling and tend to crack or shatter.

What's the best way to go about this?

How much larger must the hole be? I've used swivel-tip deburring tools to enlarge holes in thin sheet metal.

http://www.noga.com/nogaProducts.php?prdID=NG1003

[Alabam]

Check these rotary files, especially the Cylindrical Ball Nose, i use them on a Table router.
Just lock the pickup cover hole over the tip of the File and wind your Router up through the cover hole.

http://www.discount-tools.com/rfilesindexmain1.htm,

[Zhangliqun]

22 caliber rifle. Works every time!

Remind me not to make you mad, even from a distance!

[Zhangliqun]

How much larger must the hole be? I've used swivel-tip deburring tools to enlarge holes in thin sheet metal.

http://www.noga.com/nogaProducts.php?prdID=NG1003

Ideally 1/4", but that's so big that the mount screws probably wouldn't fit between the rods so I'm having some rods made at a slightly smaller diameter.

[Zhangliqun]

A reamer would work.

That was my first thought. I suppose I would need a few bits of graduating size...

[Stan H]

I use a tapered hand reamer:

http://www.hobbytool.com/index.asp?P...PROD&ProdID=28

[Spence]

Remind me not to make you mad, even from a distance!

Don't worry, I haven't shot anyone for years and in any case I can think of at least one candidate way up there on the list before I ever get to you Zhang!

[David Schwab]

I use a tapered hand reamer:

http://www.hobbytool.com/index.asp?P...PROD&ProdID=28

That's what I had in mind. A lot cleaner and more control than a drill bit. Regular twist drills don't always work well in plastic because of the rake angle on the tip.

[Zhangliqun]

Regular twist drills don't always work well in plastic because of the rake angle on the tip.

You got that right...

The hand reamer looks like a winner though. Thanks boys...

[Joe Gwinn]

Ideally 1/4", but that's so big that the mount screws probably wouldn't fit between the rods so I'm having some rods made at a slightly smaller diameter.

I forgot to ask - how many holes do you need to widen, total? One can buy reamers for use in a drill press, and of almost any possible diameter. Likewise hand reamers. If one is making a lot of holes, a reamer of the correct diameter is very much faster than being careful with a tapered reamer.

[TD_Madden]

thought they did away with personally-owned firearms in the UK....<ducks>